GM 19152823 Switch Asm, Parking/Neutral Position & Back Up Lamp

To adjust the shift lever switch for 1994 and earlier models, place the car in neutral (N) and move the switch housing all the way to the right towards low (L) gear position, then shift it into park (P) for proper adjustment. To replace it, place selector lever in neutral, unplug electrical connectors, spread tangs on housing and remove switch. Line up the actuator on the switch and hole in shift tube; then get rear part of switch situated into cutout of lower jacket while pushing down front until two tangs go under; and finally move shift lever to park. Connect electrical connectors. In order to replace or adjust this switch on 1995 or newer models firmly apply parking brake then put selector in neutral position. Pry cable off trans shift lever ball stud, take nut off holding shifter on shaft, remove lever. Disconnect electrical connector, remove mounting bolts and slide off the switch from shaft. If necessary lightly file end of shaft. When installing a new switch with shaft still at neutral align flats of the switch with flats on shaft and lower it onto it before putting in bolts. Adjust its alignment by moving as required. Reinstalling shift lever and cable, checking starting in park and neutral first then further adjusting if necessary by slackening mount bolts a bit while turning the switch so that it works properly.

Various engine sensors and components have checking procedures,the engine coolant temperature (ECT) sensor is a thermistor that changes resistance with temperature, and a failure in the circuit can cause trouble codes. The resistance should be measured when cold and warm while ensuring reference voltage from PCM is around 5.0 volts for the verification. Manifold Absolute Pressure (MAP) Sensor monitors changes in intake manifold pressure then varies its voltage output accordingly. Look at the reference voltage and signal voltage with the ignition on and engine off, and observe voltage changes as the engine's vacuum changes. Intake Air Temperature (IAT) Sensor acts as a thermistor where you can measure its resistance at different temperatures to make sure it changes as expected. Also, use a scan tool to monitor the IAT sensor for performance. The oxygen sensor in exhaust detects oxygen content which you can check its millivolt signal while warming up your engine. Check whether the oxygen sensor heater has correct voltage or not. Vehicle Speed Sensor (VSS) provides speed data to PCM which can be checked for reference voltage. Depending on the type of engine, Camshaft Sensor and Crankshaft Sensor should be checked for resistance and proper signal output. Finally, Knock Sensors detect engine knock which should be checked for reference voltage and resistance. If any component fails these checks, replacement may be necessary.

Try to start the engine in each gear. The engine should crank only in Park or Neutral. Make sure the steering column lock allows the key to go into the Lock position only when the shift lever is in Park. The ignition key should come out only in the Lock position.

Either a clutch interlock switch (manual transmission-equipped models) or a neutral safety switch (automatic transmission equipped models) is used for the neutral safety switch on these models. The engine won't crank if it's fitted with a clutch interlock switch unless the clutch is pressed. An engine with neutral safety switch can not be cranked unless the gear selector is in either park or neutral. In case of an automatic transmission vehicle, try to start it up while changing gears. It should only crank in either neutral or park. If however it starts when on any other gear then its' neutral safety switch might be faulty or need adjustment. When this happens, locate and place the shift lever in "neutral" if your car has a manual transmission. The engine will only crank when the pedal is depressed. If it cranks before you press down the pedal, this switch located near the top of the clutch pedal arm may be defective. For automatic transmissions make sure that the steering column lock allows the key to go into Lock position only when shifter lever is put on Park position. The ignition key should come out only in Lock position.

To check the Park/Neutral switch, first, ensure that it prevents the engine from starting in any gear other than Park or Neutral. Raise the vehicle and securely place it on jack stands, then unplug the electrical connector from the Park/Neutral switch. Use an ohmmeter to check continuity across the indicated switch terminals. There should be continuity with the shift lever in Park or Neutral, and no continuity in any other position. If the switch doesn't operate as described, try adjusting it before retesting, and if it still fails, replace it. For removal, apply the parking brake, place the shift lever in Neutral, disconnect the battery cable, raise the vehicle on jack stands, remove the nut and manual lever, unplug the electrical connector from the switch, and remove the switch retaining bolts. Slide the switch off the manual shaft. Installation involves using a special adjustment tool, aligning the switch with the manual shaft flats, sliding it onto the manual shaft, and securing it with mounting bolts. Remove the adjustment tool and complete the remaining installation steps, tightening the manual lever retaining nut to the specified torque.

To remove the Park/Neutral switch on 1994 models, unplug the electrical connector and pull the switch straight out of the steering column. Align the actuator with the holes in the shift tube, press down on the front of the switch until the tangs snap into the rectangular holes in the steering column jacket.

The neutral start switch prevents the engine from being cranked unless the gear selector is in Park or Neutral.

Firmly apply the parking brake and set the shift lever to Neutral. Pry the shift cable from the transmission shift lever ball-stud, remove the nut retaining the shift lever to the shaft, and take off the lever. Disconnect the electrical connector, remove the mounting bolts, and slide the switch off the shaft. Lightly file the shaft's end if needed. To install the switch with the shaft still in Neutral, align the switch's flats with those on the shaft, lower the switch onto the shaft, and install the bolts. Adjust the switch's alignment by moving it as necessary. Reinstall the shift lever and cable, verify starting in Park and Neutral, and adjust further if needed by loosening the mounting bolts and rotating the switch slightly until it functions correctly.

The ignition key should come out only in the Lock position.

The engine coolant temperature (ECT) sensor is a thermistor that changes resistance with temperature. To check it, measure the resistance while cold and warm, and ensure the reference voltage from the PCM is around 5.0 volts.

If any component fails these checks, replacement may be necessary.

Installation involves using a special adjustment tool, aligning the switch with the manual shaft flats, sliding it onto the manual shaft, and securing it with mounting bolts. Remove the adjustment tool and complete the remaining installation steps, tightening the manual lever retaining nut to the specified torque.

The ignition key should come out only in the Lock position.

To remove the Park/Neutral switch on 1995 and later models, apply the parking brake, place the shift lever in Neutral, disconnect the battery cable, raise the vehicle on jack stands, remove the nut and manual lever, unplug the electrical connector from the switch, and remove the switch retaining bolts. Slide the switch off the manual shaft.

The camshaft sensor and crankshaft sensor, depending on the engine type, should be checked for resistance and proper signal output.

Make sure the steering column lock allows the key to go into the Lock position only when the shift lever is in Park.